A microphone array can spatially differentiate different sound sources, including those from users based on the direction of arrival (DOA) of the audio signals (e.g., voice) from the users. However, this method cannot identify the identity of the sound source. That is, the above method can locate the direction of sound sources, but it cannot identify the exact identity of the sound source. For example, if the sound sources are people speaking, the microphone array can determine that people are speaking, and the number of people speaking. However, who is speaking, or what the name of the person speaking is cannot be determined.